1 /*
2 * This code implements the MD5 message-digest algorithm.
3 * The algorithm is due to Ron Rivest. This code was
4 * written by Colin Plumb in 1993, no copyright is claimed.
5 * This code is in the public domain; do with it what you wish.
6 *
7 * Equivalent code is available from RSA Data Security, Inc.
8 * This code has been tested against that, and is equivalent,
9 * except that you don't need to include two pages of legalese
10 * with every copy.
11 *
12 * To compute the message digest of a chunk of bytes, declare an
13 * MD5Context structure, pass it to MD5Init, call MD5Update as
14 * needed on buffers full of bytes, and then call MD5Final, which
15 * will fill a supplied 16-byte array with the digest.
16 *
17 * Changed so as no longer to depend on Colin Plumb's `usual.h' header
18 * definitions
19 * - Ian Jackson <ian@chiark.greenend.org.uk>.
20 * Still in the public domain.
21 */
22
23 #include <string.h> /* for memcpy() */
24
25 #include "md5_utils.h"
26
27 void
byteSwap(UWORD32 * buf,unsigned words)28 byteSwap(UWORD32 *buf, unsigned words)
29 {
30 md5byte *p;
31
32 /* Only swap bytes for big endian machines */
33 int i = 1;
34
35 if (*(char *)&i == 1)
36 return;
37
38 p = (md5byte *)buf;
39
40 do
41 {
42 *buf++ = (UWORD32)((unsigned)p[3] << 8 | p[2]) << 16 |
43 ((unsigned)p[1] << 8 | p[0]);
44 p += 4;
45 }
46 while (--words);
47 }
48
49 /*
50 * Start MD5 accumulation. Set bit count to 0 and buffer to mysterious
51 * initialization constants.
52 */
53 void
MD5Init(struct MD5Context * ctx)54 MD5Init(struct MD5Context *ctx)
55 {
56 ctx->buf[0] = 0x67452301;
57 ctx->buf[1] = 0xefcdab89;
58 ctx->buf[2] = 0x98badcfe;
59 ctx->buf[3] = 0x10325476;
60
61 ctx->bytes[0] = 0;
62 ctx->bytes[1] = 0;
63 }
64
65 /*
66 * Update context to reflect the concatenation of another buffer full
67 * of bytes.
68 */
69 void
MD5Update(struct MD5Context * ctx,md5byte const * buf,unsigned len)70 MD5Update(struct MD5Context *ctx, md5byte const *buf, unsigned len)
71 {
72 UWORD32 t;
73
74 /* Update byte count */
75
76 t = ctx->bytes[0];
77
78 if ((ctx->bytes[0] = t + len) < t)
79 ctx->bytes[1]++; /* Carry from low to high */
80
81 t = 64 - (t & 0x3f); /* Space available in ctx->in (at least 1) */
82
83 if (t > len)
84 {
85 memcpy((md5byte *)ctx->in + 64 - t, buf, len);
86 return;
87 }
88
89 /* First chunk is an odd size */
90 memcpy((md5byte *)ctx->in + 64 - t, buf, t);
91 byteSwap(ctx->in, 16);
92 MD5Transform(ctx->buf, ctx->in);
93 buf += t;
94 len -= t;
95
96 /* Process data in 64-byte chunks */
97 while (len >= 64)
98 {
99 memcpy(ctx->in, buf, 64);
100 byteSwap(ctx->in, 16);
101 MD5Transform(ctx->buf, ctx->in);
102 buf += 64;
103 len -= 64;
104 }
105
106 /* Handle any remaining bytes of data. */
107 memcpy(ctx->in, buf, len);
108 }
109
110 /*
111 * Final wrapup - pad to 64-byte boundary with the bit pattern
112 * 1 0* (64-bit count of bits processed, MSB-first)
113 */
114 void
MD5Final(md5byte digest[16],struct MD5Context * ctx)115 MD5Final(md5byte digest[16], struct MD5Context *ctx)
116 {
117 int count = ctx->bytes[0] & 0x3f; /* Number of bytes in ctx->in */
118 md5byte *p = (md5byte *)ctx->in + count;
119
120 /* Set the first char of padding to 0x80. There is always room. */
121 *p++ = 0x80;
122
123 /* Bytes of padding needed to make 56 bytes (-8..55) */
124 count = 56 - 1 - count;
125
126 if (count < 0) /* Padding forces an extra block */
127 {
128 memset(p, 0, count + 8);
129 byteSwap(ctx->in, 16);
130 MD5Transform(ctx->buf, ctx->in);
131 p = (md5byte *)ctx->in;
132 count = 56;
133 }
134
135 memset(p, 0, count);
136 byteSwap(ctx->in, 14);
137
138 /* Append length in bits and transform */
139 ctx->in[14] = ctx->bytes[0] << 3;
140 ctx->in[15] = ctx->bytes[1] << 3 | ctx->bytes[0] >> 29;
141 MD5Transform(ctx->buf, ctx->in);
142
143 byteSwap(ctx->buf, 4);
144 memcpy(digest, ctx->buf, 16);
145 memset(ctx, 0, sizeof(*ctx)); /* In case it's sensitive */
146 }
147
148 #ifndef ASM_MD5
149
150 /* The four core functions - F1 is optimized somewhat */
151
152 /* #define F1(x, y, z) (x & y | ~x & z) */
153 #define F1(x, y, z) (z ^ (x & (y ^ z)))
154 #define F2(x, y, z) F1(z, x, y)
155 #define F3(x, y, z) (x ^ y ^ z)
156 #define F4(x, y, z) (y ^ (x | ~z))
157
158 /* This is the central step in the MD5 algorithm. */
159 #define MD5STEP(f,w,x,y,z,in,s) \
160 (w += f(x,y,z) + in, w = (w<<s | w>>(32-s)) + x)
161
162 /*
163 * The core of the MD5 algorithm, this alters an existing MD5 hash to
164 * reflect the addition of 16 longwords of new data. MD5Update blocks
165 * the data and converts bytes into longwords for this routine.
166 */
167 void
MD5Transform(UWORD32 buf[4],UWORD32 const in[16])168 MD5Transform(UWORD32 buf[4], UWORD32 const in[16])
169 {
170 register UWORD32 a, b, c, d;
171
172 a = buf[0];
173 b = buf[1];
174 c = buf[2];
175 d = buf[3];
176
177 MD5STEP(F1, a, b, c, d, in[0] + 0xd76aa478, 7);
178 MD5STEP(F1, d, a, b, c, in[1] + 0xe8c7b756, 12);
179 MD5STEP(F1, c, d, a, b, in[2] + 0x242070db, 17);
180 MD5STEP(F1, b, c, d, a, in[3] + 0xc1bdceee, 22);
181 MD5STEP(F1, a, b, c, d, in[4] + 0xf57c0faf, 7);
182 MD5STEP(F1, d, a, b, c, in[5] + 0x4787c62a, 12);
183 MD5STEP(F1, c, d, a, b, in[6] + 0xa8304613, 17);
184 MD5STEP(F1, b, c, d, a, in[7] + 0xfd469501, 22);
185 MD5STEP(F1, a, b, c, d, in[8] + 0x698098d8, 7);
186 MD5STEP(F1, d, a, b, c, in[9] + 0x8b44f7af, 12);
187 MD5STEP(F1, c, d, a, b, in[10] + 0xffff5bb1, 17);
188 MD5STEP(F1, b, c, d, a, in[11] + 0x895cd7be, 22);
189 MD5STEP(F1, a, b, c, d, in[12] + 0x6b901122, 7);
190 MD5STEP(F1, d, a, b, c, in[13] + 0xfd987193, 12);
191 MD5STEP(F1, c, d, a, b, in[14] + 0xa679438e, 17);
192 MD5STEP(F1, b, c, d, a, in[15] + 0x49b40821, 22);
193
194 MD5STEP(F2, a, b, c, d, in[1] + 0xf61e2562, 5);
195 MD5STEP(F2, d, a, b, c, in[6] + 0xc040b340, 9);
196 MD5STEP(F2, c, d, a, b, in[11] + 0x265e5a51, 14);
197 MD5STEP(F2, b, c, d, a, in[0] + 0xe9b6c7aa, 20);
198 MD5STEP(F2, a, b, c, d, in[5] + 0xd62f105d, 5);
199 MD5STEP(F2, d, a, b, c, in[10] + 0x02441453, 9);
200 MD5STEP(F2, c, d, a, b, in[15] + 0xd8a1e681, 14);
201 MD5STEP(F2, b, c, d, a, in[4] + 0xe7d3fbc8, 20);
202 MD5STEP(F2, a, b, c, d, in[9] + 0x21e1cde6, 5);
203 MD5STEP(F2, d, a, b, c, in[14] + 0xc33707d6, 9);
204 MD5STEP(F2, c, d, a, b, in[3] + 0xf4d50d87, 14);
205 MD5STEP(F2, b, c, d, a, in[8] + 0x455a14ed, 20);
206 MD5STEP(F2, a, b, c, d, in[13] + 0xa9e3e905, 5);
207 MD5STEP(F2, d, a, b, c, in[2] + 0xfcefa3f8, 9);
208 MD5STEP(F2, c, d, a, b, in[7] + 0x676f02d9, 14);
209 MD5STEP(F2, b, c, d, a, in[12] + 0x8d2a4c8a, 20);
210
211 MD5STEP(F3, a, b, c, d, in[5] + 0xfffa3942, 4);
212 MD5STEP(F3, d, a, b, c, in[8] + 0x8771f681, 11);
213 MD5STEP(F3, c, d, a, b, in[11] + 0x6d9d6122, 16);
214 MD5STEP(F3, b, c, d, a, in[14] + 0xfde5380c, 23);
215 MD5STEP(F3, a, b, c, d, in[1] + 0xa4beea44, 4);
216 MD5STEP(F3, d, a, b, c, in[4] + 0x4bdecfa9, 11);
217 MD5STEP(F3, c, d, a, b, in[7] + 0xf6bb4b60, 16);
218 MD5STEP(F3, b, c, d, a, in[10] + 0xbebfbc70, 23);
219 MD5STEP(F3, a, b, c, d, in[13] + 0x289b7ec6, 4);
220 MD5STEP(F3, d, a, b, c, in[0] + 0xeaa127fa, 11);
221 MD5STEP(F3, c, d, a, b, in[3] + 0xd4ef3085, 16);
222 MD5STEP(F3, b, c, d, a, in[6] + 0x04881d05, 23);
223 MD5STEP(F3, a, b, c, d, in[9] + 0xd9d4d039, 4);
224 MD5STEP(F3, d, a, b, c, in[12] + 0xe6db99e5, 11);
225 MD5STEP(F3, c, d, a, b, in[15] + 0x1fa27cf8, 16);
226 MD5STEP(F3, b, c, d, a, in[2] + 0xc4ac5665, 23);
227
228 MD5STEP(F4, a, b, c, d, in[0] + 0xf4292244, 6);
229 MD5STEP(F4, d, a, b, c, in[7] + 0x432aff97, 10);
230 MD5STEP(F4, c, d, a, b, in[14] + 0xab9423a7, 15);
231 MD5STEP(F4, b, c, d, a, in[5] + 0xfc93a039, 21);
232 MD5STEP(F4, a, b, c, d, in[12] + 0x655b59c3, 6);
233 MD5STEP(F4, d, a, b, c, in[3] + 0x8f0ccc92, 10);
234 MD5STEP(F4, c, d, a, b, in[10] + 0xffeff47d, 15);
235 MD5STEP(F4, b, c, d, a, in[1] + 0x85845dd1, 21);
236 MD5STEP(F4, a, b, c, d, in[8] + 0x6fa87e4f, 6);
237 MD5STEP(F4, d, a, b, c, in[15] + 0xfe2ce6e0, 10);
238 MD5STEP(F4, c, d, a, b, in[6] + 0xa3014314, 15);
239 MD5STEP(F4, b, c, d, a, in[13] + 0x4e0811a1, 21);
240 MD5STEP(F4, a, b, c, d, in[4] + 0xf7537e82, 6);
241 MD5STEP(F4, d, a, b, c, in[11] + 0xbd3af235, 10);
242 MD5STEP(F4, c, d, a, b, in[2] + 0x2ad7d2bb, 15);
243 MD5STEP(F4, b, c, d, a, in[9] + 0xeb86d391, 21);
244
245 buf[0] += a;
246 buf[1] += b;
247 buf[2] += c;
248 buf[3] += d;
249 }
250
251 #endif
252